Bacterial respiratory infections are thought to be acquired by inhaling fine droplets from the mouth and throat into the lungs. These droplets contain bacteria that can breed and multiply within the lungs to cause damage.
Recent research suggests that bacteria found in the throat and mouth, can be drawn into the lower respiratory tract. This can cause infections or worsen existing lung conditions. Scientists have found that bacteria that grow in the mouth can be inhaled into the lung to cause respiratory diseases; the damaged lungs cannot effectively eliminate the bacteria and thus are more susceptible to additional lung infections.
Bacteria from the mouth have been shown to cause pneumonia, especially in individuals with existing periodontal disease. Further research is being done to learn to what extent periodontal disease may contribute to frequent occurrences of respiratory diseases.
Chronic obstructive pulmonary diseases (COPD) cause persistent obstruction of the airways. The main cause of this disease is thought to be long-term smoking. Scientists believe that through the inhaling process, bacteria can cause recurrent bouts of infection in patients with COPD. Studies are now in progress to learn to what extent oral hygiene and periodontal disease may be associated with more frequent bouts of respiratory disease in COPD patients.